A clot in the blood vessels in the brain cuts off the supply of oxygen and nutrients to brain cells, which can cause them to die. The damage to the brain that this causes is called an ischemic stroke. Most ischemic strokes happen when a clot blocks one of the arteries that carry blood to the brain, most commonly a branch of the internal carotid artery. This robs the brain of its vital blood supply, and most brain cells die if they are deprived of blood for more than four and a half hours (this is known as the time to intervention limit).
People who suffer ischemic stroke often recover all or most of their normal functions, depending on how much damage the stroke caused. Some are left with serious problems, such as poor balance or difficulty walking. Others may have emotional or memory problems.
Doctors must rapidly determine what type of stroke you have, and how bad the damage is. They will use a scanner to check the condition of your brain (magnetic resonance imaging [MRI]), an X-ray of your neck and chest (CT scan) and blood tests (including cholesterol, triglycerides, and a liver function test). They will also ask about any health conditions that might have made you more likely to have a stroke, such as atrial fibrillation, high blood pressure, or heart defects such as mitral regurgitation or ventricular septal defect.
If you have an ischemic stroke, your doctor will consider giving you a drug that breaks up blood clots or makes the blood less likely to clot (thrombolytic therapy). The sooner this is started, the more brain tissue is saved, and the better your chance of recovery. The drug most often used is tissue plasminogen activator (tPA). However, many people who have an ischemic stroke don’t reach hospital in time to get this treatment, as they might not know they are having a stroke and don’t call for help immediately.
In some cases, doctors can remove a blood clot that is blocking an artery in the neck, using a procedure called mechanical thrombectomy. This is usually done within six hours of the start of symptoms, but it can be performed earlier if other diagnostic tests show undamaged brain tissue.
Most ischemic strokes are caused by narrowing of the arteries that carry blood to your brain (carotid artery disease). This is due to a build-up of fatty materials, which is also known as atherosclerosis. Your medical team will probably recommend that you take medicines to lower your blood pressure and cholesterol. They might also suggest that you have surgery to unblock the artery in your neck, a procedure called carotid endarterectomy.
